An imaging apparatus such as a digital still camera is equipped with a lens barrel. Some of the lens barrels house various kinds of lenses like a zoom lens, and can move in an optical axis direction of a camera body. Such a lens barrel sometimes is called a “collapsible lens barrel”.
Patent Document 1 discloses a collapsible lens barrel. The collapsible lens barrel disclosed by Patent Document 1 includes a holding frame for holding a lens and a cam ring where the holding frame is incorporated. The holding frame is extendable with respect to the cam ring by the action of the cam.
In such a collapsible lens barrel, the thickness of the lens holding frame constituting the lens barrel affects the thickness of the digital still camera. This is because, in a collapsed state, the lens holding frame is received inside a housing of the digital still camera. Therefore, in order to reduce the thickness of the digital still camera, the lens holding frame is required to be made thinner.    [Patent Document 1] JP 2003-315660 A